I've just changed the cambelt, tensioner, idler and crankshaft sprocket on my ZX 1.9D, 1993 (XUD). I've rotated the roadwheel, with the car in fifth gear, and watched the cambelt on the sprockets. The belt seems to be running slightly off the edge on the diesel pump sprocket. It's only overhanging by about 1 mm but I would prefer if it was completely on the sprocket. It's hanging off towards the offside wing. The belt is ok on the cam sprocket. It's on the cam sprocket by a millimetre or two.
I wonder whether this might be due to the belt being a bit too tight? Does a belt that's too tight tend to come off the edge of the sprocket? The reason I think it might be too tight is that I can see that the bolt head in the tensioner slot is all the way to the (tight) end of the slot. There may be a bit more adjustment left but I can't see because the slot is completely under the bolt head on that end. Is it normal to have the tensioner slot in this position on a new belt?
The belt sounds a bit tighter than the previous one I fitted. I recorded the sound on my mp3 player/recorder. I'll check the frequency on my computer tomorrow. Anybody know what frequency the ZX belt should be?
When I changed the tensioner I pushed the plunger and spring in and out a few times in case it was seized. I don't think it was seized but I suppose I may have freed up the plunger a bit and that might be why I'm getting more tension now. Maybe the previous belt was too slack.
When I put the belt on I followed the procedure in the Haynes manual. When you first release the tensioner there's a lot of slack in the belt around the tensioner roller which the tensioner will take up. However you then have to rotate the engine twice which equalises the tension around the entire length of the belt. Then you release and tighten the tensioner again. I'm wondering whether the tensioner came out to maximum due to a large amount of slack in the belt around the tensioner roller at first, and then stuck in this high tension position. Maybe I need to move the tensioner by hand to help it equalise now that the belt has rotated a few times. Has anybody had problems with too much tension from the auto-tensioner?
The tensioner and idler are made by LuK (INA), from gsfcarparts. I cleaned the backplate with a Scotch Brite pad before fitting the tensioner and idler to remove any muck that might stop then sitting flat.
Paul
ZX Cambelt Questions
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the_weaver
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Some more questions. What's the best way to stop the engine from starting? I'd like to turn the engine over on the starter motor a few times to check the belt is running ok before I start the engine. I don't want to rely on using no glowplugs as my car will start with no glowplugs in the summer. Can I disconnect the diesel stop solenoid? Is it just one wire? Is it guaranteed to stop the car starting? If I turned the engine over quite a few times on the starter motor would this lead to a build up of diesel in the cylinders which might cause the car to over-rev or run out of contol?
Paul
Paul
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citroenxm
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Have you tightened BOTH Bolts on the Tensioner??
Thats the pivot one and also the one right under the Cam sprocket?? Ive noticed it can run like this if they BOTH are not tightened...
You can dissconnect the STOP solinoid wire on the end of the pump... One 8mm nut, this will stop the fuel going to the injectors... it may be under a little rubber car, just above the 4 injector pipe outlets..
Paul
Thats the pivot one and also the one right under the Cam sprocket?? Ive noticed it can run like this if they BOTH are not tightened...
You can dissconnect the STOP solinoid wire on the end of the pump... One 8mm nut, this will stop the fuel going to the injectors... it may be under a little rubber car, just above the 4 injector pipe outlets..
Paul
Sharing a pug 207 1.6 hdi Sw 16v.
M reg Xm 2.1 td auto exclusive S2 269k and rising
L reg XM V6 12v SEi auto .. Light project
A very sad...
1994 XM 2.1 d auto
M reg Xm 2.1 td auto exclusive S2 269k and rising
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A very sad...
1994 XM 2.1 d auto
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the_weaver
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Paul
Thanks for the info on the stop solenoid.
Yes, I did tighten up both the tensioner adjuster bolt and the pivot nut. I'll have another go at slackening/tightening them to see if that's the problem. I did the adjustment bolt first followed by the pivot nut. Is there a preferred sequence?
I think the round ferrule on the tensioner at the pivot point might be a bit shorter in height on this new tensioner. Not sure about that but I seem to remember that they were slightly different. It just means that the nut has to tightened a bit more over previously unused threads.
One thing I didn't do was to use a torque wrench, as I haven't got one that will go down to 18Nm, or one that will fit in the space available. So I tightened them by hand, but I probably overtightened them a bit, knowing me. Would overtightening them have any detrimental effects? I assume the tensioner body fits flat onto the backplate so you can tighten the bolts as much as you want, as long as you don't strip the threads. However, I suppose the centre pivot bolt might have a raised bit to keep the tensioner away from the backplate slightly. In which case then overtightening the adjuster bolt would pull the tensioner over at an angle.
Paul
Thanks for the info on the stop solenoid.
Yes, I did tighten up both the tensioner adjuster bolt and the pivot nut. I'll have another go at slackening/tightening them to see if that's the problem. I did the adjustment bolt first followed by the pivot nut. Is there a preferred sequence?
I think the round ferrule on the tensioner at the pivot point might be a bit shorter in height on this new tensioner. Not sure about that but I seem to remember that they were slightly different. It just means that the nut has to tightened a bit more over previously unused threads.
One thing I didn't do was to use a torque wrench, as I haven't got one that will go down to 18Nm, or one that will fit in the space available. So I tightened them by hand, but I probably overtightened them a bit, knowing me. Would overtightening them have any detrimental effects? I assume the tensioner body fits flat onto the backplate so you can tighten the bolts as much as you want, as long as you don't strip the threads. However, I suppose the centre pivot bolt might have a raised bit to keep the tensioner away from the backplate slightly. In which case then overtightening the adjuster bolt would pull the tensioner over at an angle.
Paul
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citroenxm
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In honesty, as its an XUD and uses METAL tensioner and roller, I personally have never seen the need to change them, and NEVER had a failiure too!!
They werent built like these newer things with plastic rollers!!
However, your preference, incidentally, did you notice any play in the one you removed??
as for tightening them up, Ive never used a wrench either and always tightened them up be hand! Ive always tightened up the Pivot first then the upper nut.. Are you certain the tensioner is sitting square against the block, and theres nothing behind it??
Paul
They werent built like these newer things with plastic rollers!!
However, your preference, incidentally, did you notice any play in the one you removed??
as for tightening them up, Ive never used a wrench either and always tightened them up be hand! Ive always tightened up the Pivot first then the upper nut.. Are you certain the tensioner is sitting square against the block, and theres nothing behind it??
Paul
Sharing a pug 207 1.6 hdi Sw 16v.
M reg Xm 2.1 td auto exclusive S2 269k and rising
L reg XM V6 12v SEi auto .. Light project
A very sad...
1994 XM 2.1 d auto
M reg Xm 2.1 td auto exclusive S2 269k and rising
L reg XM V6 12v SEi auto .. Light project
A very sad...
1994 XM 2.1 d auto
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the_weaver
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Paul
The car is 17 years old and has done 217K miles on the original tensioner/idler. I originally just tried changing the cambelt and wasn't going to change the tensioner or idler. However when I tried a few tension settings such as "the auto tensioner on it's own" or "the auto tensioner plus some manually added tension" it was then that I noticed that the belt seemed to be running close to or over the edge of the pump sprocket. I got the impression that there is some problem which might get worse with an increase in belt tension. So I thought it must be play in the rollers. That's why I then decided the change the tensioner and idler. The problem is still there. I think it was probably there before but it's variable depending on belt tension so it's all a bit confusing.
Originally, I got a garage to fit a new cambelt for me. However the car's performance and starting were terrible, so I took the car back and they had another go at it. The second attempt was better but still not good, so I decided to check the belt timing myself. The diesel pump sprocket was one tooth out, the cam sprocket was ok. I decided I couldn't trust the garage to try for a third time, so I took the belt off and refitted it myself.
When the garage fitted the belt, the adjustment bolt in the tensioner was around half-way or maybe two-thirds of the way across the slot. So there was plenty of adjustment on either side and I could see the slot on both sides of the bolt head. When I refitted the same belt, the bolt in the slot was almost all the way to the tight end of the slot. I thought maybe I'd stretched the belt when trying to fit it, so I decided to buy another new belt and a tensioner and idler as well. Once I've fitted those, the auto tensioner sets the tension almost all the way to the tight end of the slot again. This is the first belt I've done so I'm not experienced in checking the belt tension by feel and I haven't got a tension gauge.
I have tried recording the sound of the "plucked" belt using an mp3 recorder and analysing it on my computer. I didn't do it for the belt that the garage fitted unfortunately. The first belt that I fitted myself using the old tensioner and idler has a frequency of 73.42 Hertz. The new belt that I've just fitted (with new tensioner, idler and crankshaft sprocket) measures 106 Hertz. So obviously the belt is now tighter but I don't know what frequency range is ok. I'm wondering if the garage fitted the belt a bit loose using some non-approved method but the loose belt may have run on the sprockets ok. When I fitted the belt, tighter, using the Haynes method, the belt moves to the edge of the pump sprocket. When I fitted a new tensioner and cleaned the backplate (and added a smear of copper grease) the belt tension seems to have increased and the belt now runs 1 mm over the edge of the pump sprocket.
I don't think there's anything behind the tensioner. I did a good job of cleaning the backplate as the old tensioner felt a bit gritty when moving. I might have a go at tightening the pivot nut first, see if that makes a difference. I think the tensioner is probably sitting square but I don't know how I could check in that confined space. I made a tool to hold back the plunger when I changed the tensioner, so I didn't man-handle or lever the tensioner at all. I just dropped it into place. There was some play in the tensioner and idler that I removed. However there is also a bit of play in the ones that I put in. I'm not sure what is considered play and what is just a feeling of a slight knock in the bearing as you move the roller. The old rollers would spin freely but the new rollers are a lot heavier and don't spin much, so there's a difference there.
The garage I took the car to were not very good. I'm wondering whether they messed about with the diesel pump sprocket to "adjust" the timing rather than go through the correct process of refitting the cambelt. Would it be feasible for a garage to do a dodgy quick adjustment by removing the pump sprocket, removing the Woodruff key and turning the sprocket a bit to "fix" the incorrectly fitted cambelt? Every time I refit the belt (about four times now) the belt is always spot on on the cam sprocket but very slightly out on the diesel pump sprocket. One bolt will go into the pump sprocket, the other bolt will only go in one thread, at an angle and catches on the side of the hole. It's so close but not quite correct. If I moved it one tooth then it would be miles out. If they pulled the pump sprocket off and removed the Woodruff key then maybe the sprocket has gone back on a bit too far. I'm not sure whether the Woodruff key acts as a stop or not. Maybe it's not torqued up correctly. I'm considering removing the sprocket to have a look but I haven't got a tool to hold the sprocket or a puller to get it off.
Paul
The car is 17 years old and has done 217K miles on the original tensioner/idler. I originally just tried changing the cambelt and wasn't going to change the tensioner or idler. However when I tried a few tension settings such as "the auto tensioner on it's own" or "the auto tensioner plus some manually added tension" it was then that I noticed that the belt seemed to be running close to or over the edge of the pump sprocket. I got the impression that there is some problem which might get worse with an increase in belt tension. So I thought it must be play in the rollers. That's why I then decided the change the tensioner and idler. The problem is still there. I think it was probably there before but it's variable depending on belt tension so it's all a bit confusing.
Originally, I got a garage to fit a new cambelt for me. However the car's performance and starting were terrible, so I took the car back and they had another go at it. The second attempt was better but still not good, so I decided to check the belt timing myself. The diesel pump sprocket was one tooth out, the cam sprocket was ok. I decided I couldn't trust the garage to try for a third time, so I took the belt off and refitted it myself.
When the garage fitted the belt, the adjustment bolt in the tensioner was around half-way or maybe two-thirds of the way across the slot. So there was plenty of adjustment on either side and I could see the slot on both sides of the bolt head. When I refitted the same belt, the bolt in the slot was almost all the way to the tight end of the slot. I thought maybe I'd stretched the belt when trying to fit it, so I decided to buy another new belt and a tensioner and idler as well. Once I've fitted those, the auto tensioner sets the tension almost all the way to the tight end of the slot again. This is the first belt I've done so I'm not experienced in checking the belt tension by feel and I haven't got a tension gauge.
I have tried recording the sound of the "plucked" belt using an mp3 recorder and analysing it on my computer. I didn't do it for the belt that the garage fitted unfortunately. The first belt that I fitted myself using the old tensioner and idler has a frequency of 73.42 Hertz. The new belt that I've just fitted (with new tensioner, idler and crankshaft sprocket) measures 106 Hertz. So obviously the belt is now tighter but I don't know what frequency range is ok. I'm wondering if the garage fitted the belt a bit loose using some non-approved method but the loose belt may have run on the sprockets ok. When I fitted the belt, tighter, using the Haynes method, the belt moves to the edge of the pump sprocket. When I fitted a new tensioner and cleaned the backplate (and added a smear of copper grease) the belt tension seems to have increased and the belt now runs 1 mm over the edge of the pump sprocket.
I don't think there's anything behind the tensioner. I did a good job of cleaning the backplate as the old tensioner felt a bit gritty when moving. I might have a go at tightening the pivot nut first, see if that makes a difference. I think the tensioner is probably sitting square but I don't know how I could check in that confined space. I made a tool to hold back the plunger when I changed the tensioner, so I didn't man-handle or lever the tensioner at all. I just dropped it into place. There was some play in the tensioner and idler that I removed. However there is also a bit of play in the ones that I put in. I'm not sure what is considered play and what is just a feeling of a slight knock in the bearing as you move the roller. The old rollers would spin freely but the new rollers are a lot heavier and don't spin much, so there's a difference there.
The garage I took the car to were not very good. I'm wondering whether they messed about with the diesel pump sprocket to "adjust" the timing rather than go through the correct process of refitting the cambelt. Would it be feasible for a garage to do a dodgy quick adjustment by removing the pump sprocket, removing the Woodruff key and turning the sprocket a bit to "fix" the incorrectly fitted cambelt? Every time I refit the belt (about four times now) the belt is always spot on on the cam sprocket but very slightly out on the diesel pump sprocket. One bolt will go into the pump sprocket, the other bolt will only go in one thread, at an angle and catches on the side of the hole. It's so close but not quite correct. If I moved it one tooth then it would be miles out. If they pulled the pump sprocket off and removed the Woodruff key then maybe the sprocket has gone back on a bit too far. I'm not sure whether the Woodruff key acts as a stop or not. Maybe it's not torqued up correctly. I'm considering removing the sprocket to have a look but I haven't got a tool to hold the sprocket or a puller to get it off.
Paul
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the_weaver
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citroenxm
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L 94 XM 2.1 TD auto total resto
2008 Peugeot 207 Sw 1.6 16v hdi. 217k and rising
2010 Peugeot 207 SW 1.6 8v HDi 161k and rising - x 71
The good thing that was designed into the XUD is the fact that the tension on hese units should be nice and TIGHT!!
If its too slack you get belt "Rattle" between the Cam and Injection sprockets... or should I say belt FLAP!
So these engines are the opposite to some newer ones that have to be set to a certain tension... Let the spring tensioner take up ALL the slack...
Paul
If its too slack you get belt "Rattle" between the Cam and Injection sprockets... or should I say belt FLAP!
So these engines are the opposite to some newer ones that have to be set to a certain tension... Let the spring tensioner take up ALL the slack...
Paul
Sharing a pug 207 1.6 hdi Sw 16v.
M reg Xm 2.1 td auto exclusive S2 269k and rising
L reg XM V6 12v SEi auto .. Light project
A very sad...
1994 XM 2.1 d auto
M reg Xm 2.1 td auto exclusive S2 269k and rising
L reg XM V6 12v SEi auto .. Light project
A very sad...
1994 XM 2.1 d auto
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the_weaver
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I tried tightening the pivot nut first, followed by the adjuster bolt. It made no difference.
I released the tensioner and moved the tensioner back against the spring a few times. I then tightened the tensioner back up. I turned the engine over twice. I then released the tensioner and retightened it again. I turned the engine over twice and checked the frequency of the cambelt. It's now 87.31 Hertz which is less than the previous reading of 106 Hertz. So I managed to get the belt a bit slacker just by trying again with the auto-tensioner. It still runs about 1mm off the edge of the pump sprocket though.
I noticed that there's a thin metal backplate behind the tensioner and the entire cambelt housing. You can move it by hand as it's so thin. There could be muck behind here I suppose but I don't think I can get it off without removing the sprockets. I've got the old design of cam covers. I'm not sure if the backplate is present in the later design of cover.
I've changed the crankshaft sprocket, as there was a bit of play in it. I put the new sprocket on by hand. So far, I've only tightened the crankshaft pulley bolt enough to turn the engine over (with the pulley fitted). I'm wondering whether this might have something to do with the belt running over the edge of the pump sprocket. Maybe if I torque and angle-torque the crankshaft pulley bolt down fully it might push the crankshaft sprocket and pulley down a bit more on the crankshaft. I'll try this tomorrow.
The other thing I'm wondering is whether I've made the tensioner too good by greasing the back of the tensioner with copper grease.
Paul
I released the tensioner and moved the tensioner back against the spring a few times. I then tightened the tensioner back up. I turned the engine over twice. I then released the tensioner and retightened it again. I turned the engine over twice and checked the frequency of the cambelt. It's now 87.31 Hertz which is less than the previous reading of 106 Hertz. So I managed to get the belt a bit slacker just by trying again with the auto-tensioner. It still runs about 1mm off the edge of the pump sprocket though.
I noticed that there's a thin metal backplate behind the tensioner and the entire cambelt housing. You can move it by hand as it's so thin. There could be muck behind here I suppose but I don't think I can get it off without removing the sprockets. I've got the old design of cam covers. I'm not sure if the backplate is present in the later design of cover.
I've changed the crankshaft sprocket, as there was a bit of play in it. I put the new sprocket on by hand. So far, I've only tightened the crankshaft pulley bolt enough to turn the engine over (with the pulley fitted). I'm wondering whether this might have something to do with the belt running over the edge of the pump sprocket. Maybe if I torque and angle-torque the crankshaft pulley bolt down fully it might push the crankshaft sprocket and pulley down a bit more on the crankshaft. I'll try this tomorrow.
The other thing I'm wondering is whether I've made the tensioner too good by greasing the back of the tensioner with copper grease.
Paul
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hi Paul, yes the differential will cause that.. if both wheels are up in the air, one turning forwards will make the other turn backwards (assuming they are both free to turn) if you stop the nearside wheel the engine will turn instead 
I remember building the technical lego 'car chassis' whem I was about 11, and picking it up and turning a back wheel and the other one rotating the other way.. confused me a bit
I remember building the technical lego 'car chassis' whem I was about 11, and picking it up and turning a back wheel and the other one rotating the other way.. confused me a bit
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That's good news that it's normal. At first, I though the clutch was slipping when the engine stopped turning, until I noticed the other wheel going backwards.
I tried torquing and then angle-torquing the crankshaft pulley bolt fully. What a pain that operation turns out to be. I bought a torque angle gauge to do the job but it's difficult to use. The gauge has got a rod to anchor the scale but the rod is too short to reach anything solid and it won't go into the holes in the pulley either. Also, you need three hands to hold everything steady and whilst doing all this you have to put a lot of force on a long bar whilst reading the scale as well. Not good at all. I can see the gauge being more useful with a windy gun as you can hold the gauge in one hand and the gun in the other hand. I've given up with the gauge and made myself a disc out of cardboard with the angle marked on it. Hopefully that will be easier.
Paul
That's good news that it's normal. At first, I though the clutch was slipping when the engine stopped turning, until I noticed the other wheel going backwards.
I tried torquing and then angle-torquing the crankshaft pulley bolt fully. What a pain that operation turns out to be. I bought a torque angle gauge to do the job but it's difficult to use. The gauge has got a rod to anchor the scale but the rod is too short to reach anything solid and it won't go into the holes in the pulley either. Also, you need three hands to hold everything steady and whilst doing all this you have to put a lot of force on a long bar whilst reading the scale as well. Not good at all. I can see the gauge being more useful with a windy gun as you can hold the gauge in one hand and the gun in the other hand. I've given up with the gauge and made myself a disc out of cardboard with the angle marked on it. Hopefully that will be easier.
Paul
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RichardW
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The angle is roughly 60° - which is conveniently one flat on the bolt, Just put a spot on the pulley next to a corner of the hex, and another on the corresponding hex, then tighten the bolt till the next corner matches the mark on the pulley. It's pretty easy to judge a 1/6th turn on the bolt, but you could always put a matching spot on the outside of the socket if you wanted.
Does it come off the sprocket right away, and then stay there, or is it gradually working out? What is the water pump like? wear in the shaft can cause it to tilt, and make the belt run off....
Does it come off the sprocket right away, and then stay there, or is it gradually working out? What is the water pump like? wear in the shaft can cause it to tilt, and make the belt run off....
Richard W